linux/net/tipc
Xin Long 56077b56cd tipc: do not update mtu if msg_max is too small in mtu negotiation
When doing link mtu negotiation, a malicious peer may send Activate msg
with a very small mtu, e.g. 4 in Shuang's testing, without checking for
the minimum mtu, l->mtu will be set to 4 in tipc_link_proto_rcv(), then
n->links[bearer_id].mtu is set to 4294967228, which is a overflow of
'4 - INT_H_SIZE - EMSG_OVERHEAD' in tipc_link_mss().

With tipc_link.mtu = 4, tipc_link_xmit() kept printing the warning:

 tipc: Too large msg, purging xmit list 1 5 0 40 4!
 tipc: Too large msg, purging xmit list 1 15 0 60 4!

And with tipc_link_entry.mtu 4294967228, a huge skb was allocated in
named_distribute(), and when purging it in tipc_link_xmit(), a crash
was even caused:

  general protection fault, probably for non-canonical address 0x2100001011000dd: 0000 [#1] PREEMPT SMP PTI
  CPU: 0 PID: 0 Comm: swapper/0 Kdump: loaded Not tainted 6.3.0.neta #19
  RIP: 0010:kfree_skb_list_reason+0x7e/0x1f0
  Call Trace:
   <IRQ>
   skb_release_data+0xf9/0x1d0
   kfree_skb_reason+0x40/0x100
   tipc_link_xmit+0x57a/0x740 [tipc]
   tipc_node_xmit+0x16c/0x5c0 [tipc]
   tipc_named_node_up+0x27f/0x2c0 [tipc]
   tipc_node_write_unlock+0x149/0x170 [tipc]
   tipc_rcv+0x608/0x740 [tipc]
   tipc_udp_recv+0xdc/0x1f0 [tipc]
   udp_queue_rcv_one_skb+0x33e/0x620
   udp_unicast_rcv_skb.isra.72+0x75/0x90
   __udp4_lib_rcv+0x56d/0xc20
   ip_protocol_deliver_rcu+0x100/0x2d0

This patch fixes it by checking the new mtu against tipc_bearer_min_mtu(),
and not updating mtu if it is too small.

Fixes: ed193ece26 ("tipc: simplify link mtu negotiation")
Reported-by: Shuang Li <shuali@redhat.com>
Signed-off-by: Xin Long <lucien.xin@gmail.com>
Acked-by: Jon Maloy <jmaloy@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2023-05-15 10:21:20 +01:00
..
addr.c tipc: introduce new unified address type for internal use 2021-03-17 11:51:04 -07:00
addr.h tipc: introduce new unified address type for internal use 2021-03-17 11:51:04 -07:00
bcast.c net: tipc: fix FB_MTU eat two pages 2021-06-28 13:31:57 -07:00
bcast.h tipc: update a binding service via broadcast 2020-06-17 08:53:34 -07:00
bearer.c tipc: add tipc_bearer_min_mtu to calculate min mtu 2023-05-15 10:21:20 +01:00
bearer.h tipc: add tipc_bearer_min_mtu to calculate min mtu 2023-05-15 10:21:20 +01:00
core.c tipc: fix use-after-free Read in tipc_named_reinit 2022-06-17 11:39:10 +01:00
core.h tipc: simplify the finalize work queue 2021-05-18 13:22:09 -07:00
crypto.c tipc: Remove completion function scaffolding 2023-02-13 18:35:15 +08:00
crypto.h net/tipc: fix tipc header files for kernel-doc 2020-12-01 15:37:41 -08:00
diag.c
discover.c treewide: Convert del_timer*() to timer_shutdown*() 2022-12-25 13:38:09 -08:00
discover.h
eth_media.c tipc: constify dev_addr passing 2021-10-13 09:40:46 -07:00
group.c tipc: update address terminology in code 2020-11-27 17:34:01 -08:00
group.h tipc: update address terminology in code 2020-11-27 17:34:01 -08:00
ib_media.c tipc: constify dev_addr passing 2021-10-13 09:40:46 -07:00
Kconfig tipc: not enable tipc when ipv6 works as a module 2020-08-16 21:04:55 -07:00
link.c tipc: do not update mtu if msg_max is too small in mtu negotiation 2023-05-15 10:21:20 +01:00
link.h tipc: simplify the finalize work queue 2021-05-18 13:22:09 -07:00
Makefile tipc: remove meaningless assignment in Makefile 2020-01-08 12:38:54 -08:00
monitor.c treewide: Convert del_timer*() to timer_shutdown*() 2022-12-25 13:38:09 -08:00
monitor.h tipc: update mon's self addr when node addr generated 2019-11-12 19:45:45 -08:00
msg.c net: tipc: replace align() with ALIGN in msg.c 2021-06-28 13:31:57 -07:00
msg.h net: tipc: remove unused static inlines 2022-01-27 13:53:27 +00:00
name_distr.c net/tipc: Remove unused struct distr_queue_item 2022-09-29 18:48:32 -07:00
name_distr.h net/tipc: fix tipc header files for kernel-doc 2020-12-01 15:37:41 -08:00
name_table.c tipc: cleanup unused function 2022-06-17 11:43:57 +01:00
name_table.h tipc: cleanup unused function 2022-06-17 11:43:57 +01:00
net.c tipc: simplify the finalize work queue 2021-05-18 13:22:09 -07:00
net.h tipc: fix a deadlock when flushing scheduled work 2020-09-07 12:08:53 -07:00
netlink_compat.c string_helpers: Move string_is_valid() to the header 2023-02-09 22:30:24 -08:00
netlink.c genetlink: start to validate reserved header bytes 2022-08-29 12:47:15 +01:00
netlink.h
node.c tipc: fix unexpected link reset due to discovery messages 2023-01-06 12:53:10 +00:00
node.h tipc: add automatic session key exchange 2020-09-18 13:58:37 -07:00
socket.c net: deal with most data-races in sk_wait_event() 2023-05-10 10:03:32 +01:00
socket.h tipc: add stricter control of reserved service types 2020-10-30 08:19:18 -07:00
subscr.c tipc:subscr.c: fix a spelling mistake 2021-06-10 13:48:43 -07:00
subscr.h tipc: fix htmldoc and smatch warnings 2021-03-29 16:28:50 -07:00
sysctl.c tipc: add automatic session key exchange 2020-09-18 13:58:37 -07:00
topsrv.c net/sock: Introduce trace_sk_data_ready() 2023-01-23 11:26:50 +00:00
topsrv.h
trace.c net/tipc: fix various kernel-doc warnings 2020-12-01 15:37:46 -08:00
trace.h tipc: add support for broadcast rcv stats dumping 2020-05-26 15:16:52 -07:00
udp_media.c tipc: add tipc_bearer_min_mtu to calculate min mtu 2023-05-15 10:21:20 +01:00
udp_media.h